Acute and chronic pharmacokinetic studies of slow release ketoprofen (Oruvail) in rheumatoid arthritis.

Slow release preparations of non-steroidal anti-inflammatory drugs are used to simplify dose regimes in the treatment of rheumatoid arthritis with the aim of improving patients compliance. This study examines the acute and chronic pharmacokinetics of slow release ketoprofen in 13 rheumatoid patients with a mean age of 59.8 years. Pharmacokinetic parameters following the first dose including Tmax which was 6.92 h (s.e.m. = 0.80), Cmax 3.87 micrograms/ml (s.e.m. = 0.54), apparent half-life 8.8 h (s.e.m. = 1.0) and AUC 41.92 micrograms.h/ml (s.e.m. = 4.02) were not significantly different from those following the last dose after 3 months of chronic treatment, when these were Tmax 6.38 h (s.e.m. = 0.84) Cmax 3.57 micrograms/ml (s.e.m. = 0.33) apparent half-life 8.8 h (s.e.m. = 1.1) and AUC 43.18 micrograms.h/ml (s.e.m. = 5.34) respectively. These results show that no accumulation of ketoprofen occurred with chronic treatment. Clinical assessments were performed in an open design and showed significant improvement in pain, articular index, grip strength and duration of morning stiffness when these parameters were compared to treatment with paracetamol during an initial washout. The drug was well tolerated although there was a trend for the haemoglobin to fall and this parameter should be monitored during therapy with ketoprofen.